We are the creators of the smallest embedded JavaScript engine - V7 (https://github.com/cesanta/v7). It allows to export existing C/C++ functionality into the JS environment and express device logic in the JS script - easily updatable, unlike monolithic firmware.
Here it is - with examples for CCS: https://github.com/cesanta/v7/tree/master/examples/TI/MSP432
We are looking for feeback and requests for ports to other devices.